VC, Cr3C2 and NbC doped WC-Co cemented carbides prepared by pulsed electric current sintering

WC-12 wt.% Co grade cemented carbides doped with 0.9 wt.% VC, NbC or Cr3C2 grain growth inhibitor were consolidated by pulsed electric current sintering (PECS), also known as spark plasma sintering (SPS), in the solid state at 1240 degrees C for 2 min. The microstructure and properties of the PECS material grades are compared with those of pressureless sintered grades, liquid phase sintered at 1420 degrees C for I h. Microstructural and hardness characterization revealed that both the chemical composition and sintering technique play an important role on the WC grain growth and final mechanical properties. To obtain a nanometer sized WC-Co microstructure, it is essential to carefully select the grain growth inhibitor in addition to the application of a fast thermal densification cycle by means of spark plasma sintering. (C) 2006 Elsevier Ltd. All rights reserved.